When a crane is not in use, it is often desired to secure it to prevent movement that may result in either damage to other objects or damage to the crane itself. This is particularly true of cranes that are located out of doors and are subject to wind forces that move them on their tracks from a parked position. A type of crane which is especially subject to wind movement is a portal crane which, by its nature, has considerable surface area which may be subjected to wind forces.
When a crane is not in use, the electrical power to it is normally turned off and, therefore, electrically operated brakes are not available to maintain the crane stationary. Mechanical parking brakes may be used, however, these add undesired complexity and maintenance to the crane. A further problem with brakes used to secure a crane while it is not in use is that when it is desired to return the crane to service, the operator may be located remotely from the brake and its release mechanism, for example, where a mechanical brake is used. There is, consequently, a need for a crane parking brake which is operable irrespective of the remote location of the crane operator, which is not dependent on electrical power, and which is simple and maintenance free.